Four sided cutter with relief

ABSTRACT

An apparatus for cutting a plastic object may include a blade. The blade may include a substantially flat base; a sloped wall coupled to and extending at an angle from the base; and a cutter edge coupled to the sloped wall. The base is recessed apart from the cutter edge. The apparatus may further include a mount for positioning the blade for cutting the plastic object. The cutter edge of the blade is for cutting the plastic object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the manufacture of plasticcontainers, and more particularly to removing extraneous plastic from amanufactured container.

2. Related Art

Conventional high speed chipless cutters used, for example, in themanufacture of plastic containers, have a blade design that can cause apull-back area to appear on the top surface of the bottle where theblade is pulled back across the surface of the finished cut after thecut is complete. This is especially true when the plastic of thecontainer is at a high enough temperature that the plastic is soft.

As seen, for example, in FIG. 1, a conventional cutter blade 100 has asubstantially flat base 102 with four cutter edges 104 a, 140 b, 104 c,and 104 d (collectively 104) at the edges of the base 102. When a cutteredge 104 cuts a plastic bottle, the pull-back area is created by thedrag of the base 102 behind the cutter edge 104.

This pull-back area may deform the plastic container, in particular, theclosing mechanism on top of the container. The pull-back area may alsootherwise cause the container or the container closure not to operateproperly. Improperly manufactured containers waste manufacturing timeand materials.

What is needed then is an improved blade that overcomes the shortcomingsof conventional solutions.

BRIEF SUMMARY OF THE INVENTION

In summary, an embodiment of the present invention may reduce thepull-back by installing a relief just past the cutting surface. Thisrelief reduces the blade contact surface against the top of the bottleduring pull-out of the blade, and presents an angled surface approach tothe inner edge of the bottle to reduce any catching as the blade ispulled out.

In an exemplary embodiment, the present invention may be a apparatus forcutting a plastic object, comprising: a blade that comprises asubstantially flat base; a sloped wall coupled to and extending at anangle from the base; and a cutter edge coupled to the sloped wall,wherein the base is recessed apart from the cutter edge; and a mount forpositioning the blade for cutting the plastic object; wherein the cutteredge is for cutting the plastic object.

In another exemplary embodiment, the present invention may be a bladefor cutting a plastic object comprising: a substantially flat base; asloped wall coupled to and extending away from the base; and a cutteredge coupled to the sloped wall, wherein the base is recessed apart fromthe cutter edge.

In another exemplary embodiment, the present invention may be a methodfor cutting a plastic object comprising: providing an apparatus thatcomprises: a blade that comprises a substantially flat base; a slopedwall coupled to and extending at an angle from the base; and a cutteredge coupled to the sloped wall, wherein the base is recessed apart fromthe cutter edge; and moving the cutter edge into contact with theplastic object, thereby cutting the plastic object.

Further objectives and advantages, as well as the structure and functionof preferred embodiments will become apparent from a consideration ofthe description, drawings, and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the following, more particular description of a preferredembodiment of the invention, as illustrated in the accompanying drawingswherein like reference numbers generally indicate identical,functionally similar, and/or structurally similar elements.

FIG. 1 depicts an exemplary embodiment of a conventional four sidedcutter blade; and

FIG. 2 depicts an exemplary four-sided cutter blade according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention are discussed in detail below. Indescribing embodiments, specific terminology is employed for the sake ofclarity. However, the invention is not intended to be limited to thespecific terminology so selected. While specific exemplary embodimentsare discussed, it should be understood that this is done forillustration purposes only. A person skilled in the relevant art willrecognize that other components and configurations can be used withoutparting from the spirit and scope of the invention. All references citedherein are incorporated by reference as if each had been individuallyincorporated.

In an exemplary embodiment, the present invention includes a cutterblade with a reduced cutter edge that touches the finished bottlesurface, and a sloped relief in the form of a sloped wall behind thecutter edge to reduce catching during the pull-out of the cutter edge.Cutter blade integrity may be maintained by a tapered back side of theblade to compensate for the relief on the front. In an exemplaryembodiment, a conventional mounting configuration may be used to mountthe blade, so that no design changes to other machinery are needed touse the cutter blade of the present invention.

As seen in FIG. 2, an exemplary embodiment of a blade 200 according tothe present invention may include a substantially flat base 202. In thisembodiment, the base 202 is square-shaped, however, in practice, theblade may have any shape and may be symmetrical or asymmetrical. Eachseparate edge of base 202 has a sloped wall 206 a, 206 b, 206 c, 206 d(collectively 206). Each sloped wall 206 is coupled at its bottom to thebase 202, and extends at an angle from the base 202. A sloped wall 206may be linearly sloped. A sloped wall 206 may alternatively becurvilinearly sloped.

A separate cutter edge 204 a, 204 b, 204 c, 204 d (collectively 204) iscoupled to each sloped wall 206 a, 206 b, 206 c, 206 d, respectively.The cutter edge 204 may be made of steel. The number of sloped walls andcutter edges is generally defined by the shape of base 202. For example,a six-sided blade may have six sloped walls and six cutter edges. Asubstantially circular base may have one continuous substantiallycircular sloped wall around its circumference, with one continuoussubstantially circular cutter edge. Substantially circular includes ovaland elliptical bases.

Each cutter edge 204 is at an angle to the sloped wall 206, and candefine a plane substantially parallel to the base 202. This results inthe base 202 being recessed apart from the plane defined by the cutteredges 204. The blade 200 may also have a mount 208 for positioning theblade 200 for cutting the plastic object.

In embodiments that are not substantially circular, adjacent cutteredges may be joined together at their sides to form points. In someembodiments, one or more sloped walls may not have a cutter edge.

As a result of the recessed shaped of blade 200, when the cutter edge204 is moved into contact with the plastic object, thereby cutting theplastic object, the plastic object does not substantially contact thebase 202. Therefore, when the blade 200 is moved away from the cutplastic object, no pull-back area is formed.

The blade 200 may be mounted to a conventional cutter assembly, or mayotherwise be mounted to be rotated relative to the plastic object.

The embodiments illustrated and discussed in this specification areintended only to teach those skilled in the art the best way known tothe inventors to make and use the invention. Nothing in thisspecification should be considered as limiting the scope of the presentinvention. All examples presented are representative and non-limiting.The above-described embodiments of the invention may be modified orvaried, without departing from the invention, as appreciated by thoseskilled in the art in light of the above teachings. It is therefore tobe understood that, within the scope of the claims and theirequivalents, the invention may be practiced otherwise than asspecifically described.

1. An apparatus for cutting a plastic object, comprising: a blade thatcomprises a substantially flat base; a sloped wall coupled to andextending at an angle from said base; and a cutter edge coupled to saidsloped wall, wherein said base is recessed apart from said cutter edge;and a mount for positioning said blade for cutting the plastic object;wherein said cutter edge is for cutting the plastic object.
 2. Theapparatus of claim 1, wherein said base is set back from said cutteredge for avoiding contact between said base and the plastic object. 3.The apparatus of claim 1, wherein said base has a plurality ofsubstantially straight sides, and the blade further comprises: aplurality of sloped walls, each said sloped wall extending from one ofsaid sides; and a plurality of cutter edges, each said cutter edgecoupled to a separate one of said sloped walls.
 4. The apparatus ofclaim 3, the blade further comprising a point formed where one of saidcutter edges contacts an adjacent one of said cutter edges.
 5. Theapparatus of claim 1, wherein said base has four sides, and the bladefurther comprising: four sloped walls, each wall extending from aseparate one of said four sides; and four cutter edges, each cutter edgecoupled to a separate one of said four sloped walls.
 6. The apparatus ofclaim 5, the blade further comprising four points, each of said fourpoints formed where one of said cutter edges contacts an adjacent one ofsaid cutter edges.
 7. The apparatus of claim 5, wherein said four cutteredges define a substantially square shape.
 8. The apparatus of claim 1,wherein the base is substantially circular.
 9. The apparatus of claim 1,further comprising means to rotate the blade relative to the plasticobject.
 10. The apparatus of claim 1, wherein said cutter edge comprisessteel.
 11. The apparatus of claim 1, wherein said cutter edge defines aplane substantially parallel to said base.
 12. A blade for cutting aplastic object comprising: a substantially flat base; a sloped wallcoupled to and extending away from said base; and a cutter edge coupledto said sloped wall, wherein said base is recessed apart from saidcutter edge.
 13. The blade of claim 12, wherein said sloped wall islinearly sloped.
 14. The blade of claim 12, wherein said sloped wall iscurvilinearly sloped.
 15. The blade of claim 12, wherein said cutteredge defines a plane substantially parallel to said base.
 16. A methodfor cutting a plastic object comprising: providing an apparatus thatcomprises: a blade that comprises a substantially flat base; a slopedwall coupled to and extending at an angle from said base; and a cutteredge coupled to said sloped wall, wherein said base is recessed apartfrom said cutter edge; and moving said cutter edge into contact with theplastic object, thereby cutting the plastic object.
 17. The method ofclaim 16, wherein the base does not substantially contact the plasticobject when the cutter edge cuts the plastic object.
 18. The method ofclaim 16, further comprising moving said blade away from the plasticobject that is cut.
 19. The method of claim 16, wherein said cutter edgedefines a plane substantially parallel to said base.